This invention relates to a process and product for enhancing immune response and improving the overall health of companion animals such as dogs, and more particularly, to a process and product which provides beneficial amounts of antioxidants in the animal's diet.
In recent years, there has been increasing interest in the health benefits of antioxidants. Antioxidants are nutrients that counteract the effect of reactive oxygen species (also known as free radicals). These harmful molecules are by-products of normal metabolism. Antioxidant nutrients counteract the effects of free radicals by attaching to these molecules, neutralizing them, and removing them from the body. Inefficient clean-up of free radicals has been implicated in causing damage to humans, which is believed to result in certain diseases such as Alzheimer's disease, autoimmune disease, cancer, cardiovascular disease, cataracts, diabetes, macular degeneration, multiple sclerosis, muscular dystrophy, pancreatitis, Parkinson's disease, and rheumatoid arthrititis. The damage caused by the accumulation of these free radicals may be responsible for the aging process as the accumulation of these free radicals over time causes the suppression of the immune response that occurs with age, resulting in increased incidence of disease within the senior population.
Antioxidant nutrients are a classification for a variety of compounds with a similar role of neutralizing harmful free radicals. They can include such commonly known vitamins as vitamin A, vitamin C, and vitamin E. They also include other compounds that are classified as carotenoids. Examples of carotenoids include .beta.-carotene, lutein, astaxanthin, canthoxanthin and lycopene. These compounds are responsible for developing the green, yellow, orange and pink pigmentation found in fruits, flowers and vegetables. These carotenoids are known to play an important role in modulating the immune system (for example, canthaxanthin has been found to prevent chemical-induced carcinogenesis in mice as well as increase lymphocyte proliferation in rats). Astaxanthin and .beta.-carotene have been found to increase ex vivo antibody response of mouse splenocytes to T-dependent antigens. Dietary lutein has been found to enhance lymphocyte proliferation in mouse splenocytes.
Although these compounds are all classified as antioxidants, it has become apparent that they do not all function in the same way. For instance, historical studies in humans show that populations consuming diets high in antioxidants (i.e., high intake of fruits and vegetables) have a lower incidence of cancer than other groups of people. However, clinical studies that provide supplementation with antioxidants such as vitamin E or .beta.-carotene alone do not provide the same magnitude of protection. It is currently believed that a human health benefit from antioxidant nutrients may be through a combination of several different antioxidants at low levels rather than one antioxidant at high levels.
Although the dog has not evolved on a diet based on high quantities of fruits and vegetables, it did hunt and eat small herbivores that consumed plants having high concentrations of these compounds. Therefore, it is possible that the dog's need for antioxidants evolved naturally. Accordingly, there is a need in the art for providing beneficial antioxidants in the diet of a companion animal such as a dog to provide health benefits.